In T.V. dinners, a complete prepared dinner is packaged in separate compartments in a tray. Typically, separate compartments are provided for meat, potato, vegetables and desert. The foodstuffs are prepared for serving and frozen for reconstitution for consumption. A problem which has been encountered with such products is uneven heating of the foodstuffs in the compartments upon reconstitution for consumption by microwave energy, since they often cook at different rates when exposed to microwave energy. This lack of uniformity of heating is often considered undesirable by the consumer.
Various attempts have been made to improve the uniformity of heating of the foodstuffs in the compartments by the application of microwave energy thereto. In this regard, a search of the records of the U.S. Patent and Trademark Office has revealed the following U.S. Patents as the closest prior art:
______________________________________ 3,079,913; 3,219,460; 3,240,610; 3,271,169; 3,398,041; 3,615,713; 3,672,916; 3,799,143; 4,013,798; 4,555,605; 4,626,641; 4,656,325; 4,703,148; 4,676,857; and 4,703,149 ______________________________________
In addition, the Examiner has cited the following addition prior art in the grand-parent application:
______________________________________ U.S. Pat. No. 4,656,325; 4,735,513; 4,190,757; 4,676,857 3,219,460; 3,941,967; and 4,495,392 ______________________________________
These prior art references describe a variety of microwave energy shielding and focussing devices for the purposes of redistribution of microwave energy to the prepared foodstuffs in the T.V. dinner tray.
One proposal for dealing with the problem of uneven heating is described in the aforementioned U.S. Pat. No. 4,656,325. In this patent, there is described the provision of a lid structure having a plurality of metal islands and which is arranged to be spaced from the foodstuff in the holding pan so as to permit microwave energy to pass through the cover onto the package without interfering with internal reflections of the microwave energy within the package by the metal islands.
This prior art structure is expensive to manufacture and cumbersome to employ. Others of the prior art structures simply are not effective to produce the desired result.